public class Test {
    import java.util.*;

    /**
     * @Author 12629
     * @Description：
     */
    public class BinaryTree {

        static class TreeNode {
            public char val;
            public TreeNode left;
            public TreeNode right;

            public TreeNode(char val) {
                this.val = val;
            }
        }
        public TreeNode createTree() {
            TreeNode A = new TreeNode('A');
            TreeNode B = new TreeNode('B');
            TreeNode C = new TreeNode('C');
            TreeNode D = new TreeNode('D');
            TreeNode E = new TreeNode('E');
            TreeNode F = new TreeNode('F');
            TreeNode G = new TreeNode('G');
            TreeNode H = new TreeNode('H');
            A.left = B;
            A.right = C;
            B.left = D;
            B.right = E;
            C.left = F;
            C.right = G;
            //E.right = H;
            return A;
        }

    /*public static int i = 0;
    public static TreeNode createTree(String str) {
        TreeNode root = null;
        if(str.charAt(i) != '#') {
            root = new TreeNode(str.charAt(i));
            i++;
            root.left = createTree(str);
            root.right = createTree(str);
        }else {
            i++;
        }
        return root;
    }*/

        // 前序遍历
        public void preOrder(TreeNode root) {
            if(root == null) return;
            System.out.print(root.val+" ");
            preOrder(root.left);
            preOrder(root.right);
        }

        // 中序遍历
        public void inOrder(TreeNode root) {
            if(root == null) return;
            inOrder(root.left);
            System.out.print(root.val+" ");
            inOrder(root.right);
        }

        // 后序遍历
        public void postOrder(TreeNode root) {
            if(root == null) return;
            postOrder(root.left);
            postOrder(root.right);
            System.out.print(root.val+" ");
        }


        public int nodeSize;
        /**
         * 遍历思路
         * 获取当前二叉树的节点个数
         * @param root
         * @return
         */
        public void getNodeSize(TreeNode root) {
            if(root == null) return ;
            nodeSize++;
            getNodeSize(root.left);
            getNodeSize(root.right);
        }

        public int getNodeSize2(TreeNode root) {
            if(root == null) return 0;
            return getNodeSize2(root.left) +
                    getNodeSize2(root.right) + 1;
        }

        public int leafCount;
        /**
         * 获取叶子节点的个数 - 遍历思路
         * @param root
         */
        public void getLeafNodeCount(TreeNode root) {
            if(root == null) {
                return;
            }
            if(root.left == null && root.right == null) {
                leafCount++;
            }
            getLeafNodeCount(root.left);
            getLeafNodeCount(root.right);
        }

        /**
         * 获取叶子节点的个数  - 子问题
         * @param root
         * @return
         */
        public int getLeafNodeCount2(TreeNode root) {
            if(root == null) {
                return 0;
            }
            if(root.left == null && root.right == null) {
                return 1;
            }
            return getLeafNodeCount2(root.left) +
                    getLeafNodeCount2(root.right);
        }

        /**
         * 第K层节点的个数
         * @param root
         * @param k
         * @return
         */
        public int getKLevelNodeCount(TreeNode root,int k) {
            if(root == null) {
                return 0;
            }
            if(k == 1) {
                return 1;
            }
            return getKLevelNodeCount(root.left,k-1) +
                    getKLevelNodeCount(root.right,k-1);
        }

        /**
         * 二叉树的高度
         * 时间复杂度：O(N)
         * @param root
         * @return
         */
        public int getHeight(TreeNode root) {
            if(root == null) return 0;
            int leftHeight = getHeight(root.left);
            int rightHeight = getHeight(root.right);

            return Math.max(leftHeight,rightHeight) + 1;

            //return leftHeight > rightHeight ? leftHeight+1 : rightHeight+1;
            //return getHeight(root.left) > getHeight(root.right) ?
            //getHeight(root.left)+1 : getHeight(root.right)+1;
        }

        public TreeNode find(TreeNode root,char key) {
            if(root == null) {
                return null;
            }
            if(root.val == key) {
                return root;
            }
            TreeNode leftResult = find(root.left,key);
            if(leftResult != null) {
                return leftResult;
            }

            TreeNode rightResult = find(root.right,key);
            if(rightResult != null) {
                return rightResult;
            }

            return null;
        }

        // p -> m    q -> n  时间复杂度：O(min(m,n))
        public boolean isSameTree(TreeNode p, TreeNode q) {
            //1. 一个为空 一个不为空 【结构上】
            if( (p == null && q != null) || (p != null && q == null)) {
                return false;
            }
            //2. 此时 都不为空  或者 都为空 才能走到这里
            if(p == null && q == null ) {
                return true;
            }

            if(p.val != q.val) {
                return false;
            }
            //3. 此时代码走到这里  代表：p != null && q != null  && p.val == q.val
            return isSameTree(p.left,q.left) && isSameTree(p.right,q.right);
        }

        public boolean isSubtree(TreeNode root, TreeNode subRoot) {
            if(root == null)return false;
            if(isSameTree(root,subRoot)) return true;
            if(isSubtree(root.left,subRoot))return true;
            if(isSubtree(root.right,subRoot))return true;
            return false;
        }

        public TreeNode invertTree(TreeNode root) {
            if(root == null) return null;
            TreeNode tmp = root.left;
            root.left = root.right;
            root.right = tmp;

            invertTree(root.left);
            invertTree(root.right);
            return root;
        }


        public boolean isBalanced(TreeNode root) {
            if(root == null) return true;

            int leftHeight = getHeight(root.left);
            int rightHeight = getHeight(root.right);

            return Math.abs(leftHeight - rightHeight) <= 1
                    && isBalanced(root.left) && isBalanced(root.right);

        }


        public boolean isBalanced2(TreeNode root) {
            if(root == null) return true;
            return maxDepth(root) >= 0;
        }

        public int maxDepth(TreeNode root) {
            if(root == null) return 0;
            int leftHeight = maxDepth(root.left);
            if(leftHeight < 0) {
                return -1;
            }
            int rightHeight = maxDepth(root.right);
            if(leftHeight >= 0 &&  rightHeight >= 0 &&
                    Math.abs(leftHeight - rightHeight) <= 1) {
                return Math.max(leftHeight,rightHeight) + 1;
            }else {
                return -1;
            }
        }

        public boolean isSymmetric(TreeNode root) {
            if(root == null) return true;
            return isSymmetricChile(root.left,root.right);
        }

        public boolean isSymmetricChile(TreeNode leftTree,TreeNode rightTree) {
            if(leftTree == null && rightTree != null ||
                    leftTree != null && rightTree == null) {
                return false;
            }
            if(leftTree == null && rightTree == null ) {
                return true;
            }
            if(leftTree.val != rightTree.val) {
                return false;
            }
            return isSymmetricChile(leftTree.left,rightTree.right)
                    && isSymmetricChile(leftTree.right,rightTree.left);
        }

        public void levelOrder(TreeNode root) {
            if(root == null) {
                return;
            }
            Queue<TreeNode> queue = new LinkedList<>();
            queue.offer(root);
            while (!queue.isEmpty()) {
                TreeNode cur = queue.poll();
                System.out.print(cur.val+" ");
                if(cur.left != null) {
                    queue.offer(cur.left);
                }
                if(cur.right != null) {
                    queue.offer(cur.right);
                }
            }
        }


   /* public List<List<Integer>> levelOrder2(TreeNode root) {
        List<List<Integer>> ret = new ArrayList<>();
        if(root == null) {
            return ret;
        }
        Queue<TreeNode> queue = new LinkedList<>();
        queue.offer(root);
        while (!queue.isEmpty()) {
            List<Integer> tmpList= new ArrayList<>();
            int size = queue.size();
            while (size != 0) {
                TreeNode cur = queue.poll();
                size--;
                //System.out.print(cur.val+" ");
                tmpList.add(cur.val);
                if(cur.left != null) {
                    queue.offer(cur.left);
                }
                if(cur.right != null) {
                    queue.offer(cur.right);
                }

            }
            ret.add(tmpList);
        }
        return ret;
    }*/

        public boolean isCompleteTree(TreeNode root) {
            if(root == null) return true;
            Queue<TreeNode> queue = new LinkedList<>();
            queue.offer(root);

            while (!queue.isEmpty()) {
                TreeNode cur = queue.poll();
                if(cur != null) {
                    queue.offer(cur.left);
                    queue.offer(cur.right);
                }else {
                    break;
                }
            }
            while (!queue.isEmpty()) {
                TreeNode cur = queue.peek();
                if(cur == null) {
                    queue.poll();
                }else {
                    return false;
                }
            }
            return true;
        }

        public TreeNode lowestCommonAncestor(TreeNode root,
                                             TreeNode p, TreeNode q) {
            if(root == null) {
                return root;
            }
            if(root == p || root == q) {
                return root;
            }
            TreeNode leftTree = lowestCommonAncestor(root.left,p,q);
            TreeNode rightTree = lowestCommonAncestor(root.right,p,q);
            if(leftTree != null && rightTree != null) {
                return root;
            }else if(leftTree != null) {
                return leftTree;
            }else {
                return rightTree;
            }
        }

        public TreeNode lowestCommonAncestor2(TreeNode root,
                                              TreeNode p, TreeNode q) {
            Stack<TreeNode> stackP = new Stack<>();
            Stack<TreeNode> stackQ = new Stack<>();
            getPath(root,p,stackP);
            getPath(root,q,stackQ);

            int sizeP = stackP.size();
            int sizeQ = stackQ.size();
            if(sizeP > sizeQ) {
                int size = sizeP - sizeQ;
                while (size != 0) {
                    stackP.pop();
                    size--;
                }
            }else {
                int size = sizeQ - sizeP;
                while (size != 0) {
                    stackQ.pop();
                    size--;
                }
            }

            while (!stackP.isEmpty() && !stackQ.isEmpty()) {
                TreeNode val1 = stackP.pop();
                TreeNode val2 = stackQ.pop();
                if(val1 == val2) {
                    return val1;
                }
            }
            return null;
        }

        private boolean getPath(TreeNode root, TreeNode node,
                                Stack<TreeNode> stack) {
            if(root == null) {
                return false;
            }
            stack.push(root);
            if(root == node) {
                return true;
            }
            boolean flg = getPath(root.left,node,stack);
            if(flg) {
                return true;
            }
            flg = getPath(root.right,node,stack);
            if(flg) {
                return true;
            }
            stack.pop();
            return false;
        }

    /*
    class Solution {

    public int preIndex = 0;
    public TreeNode buildTree(int[] preorder, int[] inorder) {

        return buildTreeChilde(preorder,inorder,0,inorder.length-1);
    }

    public TreeNode buildTreeChilde(int[] preorder, int[] inorder,int inbegin,int inend) {

        if(inbegin > inend) {
            return null;
        }

        TreeNode root = new TreeNode(preorder[preIndex]);

        int rootIndex = findVal(inorder,inbegin,inend,preorder[preIndex]);
        preIndex++;

        root.left = buildTreeChilde(preorder,inorder,inbegin,rootIndex-1);

        root.right = buildTreeChilde(preorder,inorder,rootIndex+1,inend);

        return root;
    }

    private int findVal(int[] inorder,int inbegin,int inend,int key) {
        for(int i = inbegin; i<= inend;i++) {
            if(inorder[i] == key) {
                return i;
            }
        }
        return -1;
    }
}
     */



    /*
    class Solution {

    public int postIndex = 0;
    public TreeNode buildTree(int[] inorder, int[] postorder) {
        postIndex = postorder.length-1;

        return buildTreeChilde(postorder,inorder,0,inorder.length-1);
    }

    public TreeNode buildTreeChilde(int[] postorder, int[] inorder,int inbegin,int inend) {

        if(inbegin > inend) {
            return null;
        }

        TreeNode root = new TreeNode(postorder[postIndex]);

        int rootIndex = findVal(inorder,inbegin,inend,postorder[postIndex]);
        postIndex--;


        root.right = buildTreeChilde(postorder,inorder,rootIndex+1,inend);

        root.left = buildTreeChilde(postorder,inorder,inbegin,rootIndex-1);


        return root;
    }

    private int findVal(int[] inorder,int inbegin,int inend,int key) {
        for(int i = inbegin; i<= inend;i++) {
            if(inorder[i] == key) {
                return i;
            }
        }
        return -1;
    }
}
     */

        public String tree2str(TreeNode root) {
            StringBuilder stringBuilder = new StringBuilder();
            tree2strChild(root,stringBuilder);
            return stringBuilder.toString();
        }

        public void tree2strChild(TreeNode root,StringBuilder stringBuilder) {
            if(root == null) return;
            stringBuilder.append(root.val);
            //左子树
            if(root.left != null) {
                stringBuilder.append("(");
                tree2strChild(root.left,stringBuilder);
                stringBuilder.append(")");
            }else {
                if(root.right == null) {
                    return;
                }else {
                    stringBuilder.append("()");
                }
            }
            //右子树
            if(root.right != null) {
                stringBuilder.append("(");
                tree2strChild(root.right,stringBuilder);
                stringBuilder.append(")");
            }else {
                return;
            }
        }

        public List<Character> preorderTraversal(TreeNode root) {
            List<Character> ret = new ArrayList<>();
            if(root == null) {
                return ret;
            }
            Stack<TreeNode> stack = new Stack<>();
            TreeNode cur = root;
            while (cur != null || !stack.isEmpty()) {
                while (cur != null) {
                    stack.push(cur);
                    System.out.print(cur.val + " ");
                    ret.add(cur.val);
                    cur = cur.left;
                }
                TreeNode top = stack.pop();
                cur = top.right;
            }
            return ret;
        }

        public List<Character> inorderTraversal(TreeNode root) {
            List<Character> ret = new ArrayList<>();
            if(root == null) {
                return ret;
            }
            Stack<TreeNode> stack = new Stack<>();
            TreeNode cur = root;
            while (cur != null || !stack.isEmpty()) {
                while (cur != null) {
                    stack.push(cur);
                    cur = cur.left;
                }
                TreeNode top = stack.pop();
                System.out.print(top.val + " ");
                ret.add(top.val);
                cur = top.right;
            }
            return ret;
        }

   /* public List<Integer> postorderTraversal(TreeNode root) {
        List<Integer> ret = new ArrayList<>();
        if(root == null) {
            return ret;
        }
        Stack<TreeNode> stack = new Stack<>();
        TreeNode cur = root;
        TreeNode prev = null;
        while (cur != null || !stack.isEmpty()) {
            while (cur != null) {
                stack.push(cur);
                cur = cur.left;
            }
            TreeNode top = stack.peek();
            if(top.right == null || top.right == prev) {
                stack.pop();
                ret.add(top.val);
                prev = top;
            }else {
                cur = top.right;
            }
        }
        return ret;
    }*/
    }

}
